In my copending patent applications, a folded paperboard carton is disclosed which utilizes a unique tab and slot arrangement to securely retain drinking glasses or other objects within the carton. In this application, an improvement in paperboard cartons is disclosed whereby a carton is adapted to accommodate glassware having irregularly shaped portions such as stems, flutes, etc.
Folded paperboard cartons are commonly used as packaging for generally cylindrical objects such as cans or drinking glasses. Known cartons usually comprise a continuous sheet of paperboard wrapped around a group of glasses to form a sleeve having top and bottom panels, opposite side wall panels, and two opposite open ends for insertion and removal of the glasses. Various pieces of the sleeve panels fold inwardly against or between the glasses to hold them in place. Also, a separator panel extending between adjacent glasses is sometimes provided as an inwardly folded piece of a sleeve panel, or may be formed as a distinct panel of the carton. Examples of such carton structures are seen in U.S. Pat. Nos. 2,817,473 to Foster and 4,640,417 to Durand.
A carton is normally formed from an elongated blank sheet of paperboard. Such blank sheets have folding lines to define distinct carton panels in succession along the length of the sheet, and additional cut and scored lines to define the inwardly folding pieces of the panels. A small folding extension at one or both ends of the blank sheet can be provided as a glue flap for construction of the sheet into a closed sleeve with opposite ends thereof joined at the glue flap.
A blank sheet is constructed into a sleeve-like carton by first applying adhesive to the glue flap and then by pivoting one end of the blank sheet about a laterally extending folding line to bring that end over into engagement with the other end, whereby the blank is disposed in a flat overlapped position with the ends adhered together. The flat overlapped configuration is expanded into an open ended rectangular sleeve by moving the panels away from one another with bending action at the lateral folding lines. The glasses may then be inserted into the open ends of the sleeve, and the inwardly folding pieces appropriately engaged with the glasses.
Problems with known paperboard cartons arise with both the constructed cartons and the blank sheets. The cartons fail to provide a strong and rigid container for glasses of various shapes, and the blank sheets inefficiently require manual assembly operations after the sheets are expanded into the open sleeve configuration.
More specifically, known paperboard cartons for drinking glasses generally make no provision for stems, converging sides, or other common but irregular shapes. A glass having a narrow base can easily shift inside the carton to break against an adjacent glass or to fall out of the carton. The inwardly folding pieces of known sleeve panels have been arranged to extend between glasses or to engage the stem of a goblet, such as in U.S. Pat. Nos. 2,817,473 and 4,640,417 noted above, but removal of these pieces out of the plane of the associated sleeve panel greatly weakens the structure of the carton. A weakened carton cannot safely hold fragile drinking glasses and requires heavier and greater amounts of paperboard material to accommodate a weak structural design. In addition to weakening the panel, a stem holding piece taken from the top, bottom, or side panels of the sleeve undesirably exposes the contained glasses to impact with objects outside the carton, and when taken from an internal separator panel, a stem holding piece is difficult to reach for manipulation into place.
Known blank sheets for constructing cartons with stem holding or similar pieces inefficiently require manual manipulation of these pieces into position. Automatic equipment is used to apply adhesive to the glue flaps, and to fold the blank sheet into the overlapped flat configuration in which the cartons are stored or shipped for subsequent manual expansion and loading with drinking glasses. The manual operations of folding the stem holding pieces out of the plane of the associated panel, aligning the end or other part of the folded piece into position, and attachment thereof with adhesive are all time consuming and exacting tasks which detract from the efficiency and quality of the process.
Known cartons for drinking glasses are thus seen to fail to provide a strong and rigid container for glasses of differing shapes, or an efficient method of manufacturing such a container.